1. Field of the Invention
The present invention generally relates to color printer apparatuses, and particularly relates to a color printer apparatus which prints documents with a reduced toner amount where each document may include characters, graphics, and images simultaneously.
2. Description of the Related Art
Application software of today is generally provided with a function to generate a color document by capturing color images, characters, graphics, etc. Even if the most part of this document image is comprised of black letters, the inclusion of color graphics or color images in the document results in an increase of color toners. The related-art color printer apparatuses may thus be provided with a particular design consideration such as to skip print dots by use of a mask pattern, thereby reducing toner amounts applied to the printed document image.
As an example of such apparatus, Japanese Patent Laid-open Application No. 11-112789 teaches purging data at every other pixel in the bitmap image data representing a document image, and prints the document image by use of the partially purged image data. Since image data is not printed at the purged pixels, such printing reduces the number of actually printed pixels, thereby decreasing toner amounts.
Japanese Patent Laid-open Application No. 2001-130055 teaches a printing method in which a mode can be selected from a plurality of modes including a toner saving mode, a high picture quality mode, and so on. Even when a current setting indicates the toner saving mode, a request by a user for use of high picture quality automatically results in switching from the toner saving mode to the high picture quality mode.
In the related-art technologies as described above, toner is saved (i.e., the toner amount is reduced) over the entire image that is printed. The printed image thus results in its entire appearance being in faint color. When a print image is to be reproduced from a captured color document that includes letters, graphics, and images as previously described, some part of the printed image may need less toner amount while other part of the printed image may need a clear image appearance The related-art technologies described above are not suited to such discriminatory toner saving. It is possible to add a new control stage to existing printing control stages so as to achieve discriminatory toner saving for different parts of the image Such addition of a control stage, however, results in the processing speed being undesirably reduced, compared with the print systems that do not have such additional control step.
Accordingly, there is a need for a color printing apparatus that achieves toner saving without reducing the processing speed of color printing.
There is another need for a color printing apparatus that achieves discriminatory toner saving for different image parts without reducing the processing speed of color printing.
It is a general object of the present invention to provide a color printing apparatus that substantially obviates one or more of the problems caused by the limitations and disadvantages of the related art.
Features and advantages of the present invention will be set forth in the description which follows, and in part will become apparent from the description and the accompanying drawings, or may be learned by practice of the invention according to the teachings provided in the description. Objects as well as other features and advantages of the present invention will be realized and attained by a color printing apparatus particularly pointed out in the specification in such full, clear, concise, and exact terms as to enable a person having ordinary skill in the art to practice the invention.
To achieve these and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention provides an apparatus for printing a color image, including a printer driver which processes input image data to generate printable image data, and further including one or more color profiles which are used by the printer driver to perform color matching on the input image data in a normal mode, wherein the printer driver uses one or more toner-saving-purpose profiles to perform color matching on the input image data in a toner saving mode, the one or more toner-saving-purpose profiles being specifically designed to reduce a toner amount on a printed color image.
In the invention as described above, the printer driver operating in the toner saving mode applies the color matching process to the input image data by using the one or more toner-saving-purpose profiles. In this manner, the toner saving process is performed as part of the color matching process, without sacrificing the processing speed as in the related-art case where the toner-saving process step needs to be added to existing process steps.
According to one aspect of the present invention, the printer driver as described above includes an object identifying unit which identifies a type of an object included in the input image data, wherein the printer driver selects one of the color profiles that matches the identified type of the object so as to use the selected color profile to perform the color matching in the normal mode, and selects one of the toner-saving-purpose profiles that matches the identified type of the object so as to use the selected toner-saving-purpose profile to perform the color matching in the toner saving mode.
The invention described above makes it possible to achieve discriminatory toner saving for different image parts (i.e., image objects of different types) without reducing the processing speed of color printing. Namely, toner saving can be achieved with respect to only a selected portion of the print image while maintaining high image quality for portions that require high quality printing.
Other objects and further features of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings.